The present invention is directed to a method for controlling components of a communication system with which a multipoint-multiconnection call set up is possible. The system is composed of at least one network for transmiting digital communication signals having at least one switching equipment and of communication terminal equipment allocated to subscribers. In this context, components can be communication terminal equipment, private branch exchanges, switching equipment (switch), etc. Individual components are thereby respectively controlled by signaling information in the form of messages communicated from a different component over a part of the network. Each message contains at least one protocol and message identifier, attributes of the objects of call, of subscriber and of connection with call, subscriber and connection identification numbers, respectively, permanently allocated at least locally to the call for the duration of a call for each of the individual objects. Moreover, information about the relationships between different objects are contained in each message, for example which connections are allocated to which subscribers or which different connections should have a common route management.
In previous communication systems, a call within the network is set up from a call center or, respectively, calling subscriber to a single subscriber, whereby a single connection is provided. A simple set up of messages of the signaling information is thereby possible with a protocol and message identifier, a call number, the attributes of the called subscriber and the attributes of the connection. Beginning with the second expansion level (release 2) of the broadband ISDN referred to in the article "Integration in Drei Schritten", E. Brill, M. N. Huber, B. Petri, net 47 (1993), nos. 7-8 pp. 326-329, support is required for multipoint-multiconnection call relationships in the network.
The article "B-ISDN UNI SIGNALING SPECIFICATION BASELINE DOCUMENT FOR RELEASE TO AND BEYOND FUTURE RELEASES", ITU-Telecommunication Standardization Sector, Study Group 11, Geneva, 3-19 May 1993, discloses a control method for supporting multipoint-multiconnection call relationships in the network wherein information elements of the individual objects are hierarchically grouped within a message. As a result the control unit of a control communication system component can recognize a relationship between the individual objects on the basis of the sequence of the received information elements. This can be well-recognized in the examples for message formats of a multiconnection call and of a multisubscriber call that are shown in FIGS. 2 and 3A on pages 7 and 8 of the aforementioned baseline document. The subscriber attributes, for example, are thereby higher-ranking in FIG. 2, so that connection attributes are transmitted for every individual subscriber with information elements of the specific attributes of every individual connection that are valid for this subscriber. When provided, an identification number of a group of connections that traverse the same route in the network is undertaken for every subscriber (common route connection group). Here and in the following use of the term, an identification number means an unambiguous designation, for example a group of numerals and/or letters and/or special characters.
All connection attributes are thus transmitted per subscriber and results in substantial information redundancy. The physical signalization signals transmitted in the level 1 contain the message in the message format offered by the controlling component, so that a large number of unnecessary signalization data signals must be transmitted between the controlling component and the component to be controlled. Every additional relationship between the objects of the call, i.e. between call, subscriber and/or connection, requires an additional hierarchy level within the structure. Given partial overlap of common relationships, complications can thereby arise, particularly when a plurality of differently configured connections are to be set up on a partially shared route between a plurality of subscribers. In this case, the required signalization information contains a great deal of redundancy and a modification or, respectively, expansion of the relationships between the objects within a call requires an involved message modification.